Is it permissible for a pilgrim in the state of Ihram to comb his hair with a comb?

The pilgrim in ihram should be dishevelled and dusty, and should not comb his hair because it is prone to falling out. However, there is no harm in washing it. If a pilgrim's hair falls out unintentionally, such as from scratching or rubbing the head, there is no blame upon him, because there is no harm in the prohibitions of ihram if they occur by mistake or forgetfulness, as Allah the Almighty says: (And there is no blame upon you for that in which you have erred, but [only for] what your hearts have intended) and His saying: (Our Lord, do not take us to task if we forget or make a mistake).